Can you help me ID a bird based on a really vague description?

We only saw it for a few seconds, from the back. It was a finch- or sparrow-sized bird that appeared to have a bluish-grey back. It was accompanied by another bird, similarly sized, that was sparrow-ish in its appearance (mottled brown / whitish back).

FWIW, we live in Indianapolis, IN. If I see it again, I’ll try to get a better look or even take a picture.

My first guess on the first one would be Dark-eyed Junco. It’s not going to be possible to confirm it without a more detailed description. The second is impossible even to guess, aside from the fact that it might be a sparrow.

The white crowned sparrow is has some gray features-

How big does a junco usually get? This one was fairly small. My husband thinks it might have been an indigo bunting, but it wasn’t that bright of a blue, and it certainly wasn’t big enough to be a grosbeak. But it did seem bluer than that junco photo. I’ll keep my eye out.

Juncos are pretty small, substantially smaller than a House Sparrow. However, Indianapolis is a little far south for them in midsummer. Male Indigo Buntings are pretty bright blue (not really blue-gray) while females are brownish.